监控Nginx.md

监控Nginx

prometheus监控Nginx需要对Nginx做一些配置,才能顺利拿到Nginx的数据

环境依赖:

• Nginx源码
• lua-nginx-module
• Lua-JIT
• nginx-lua-prometheus

1.编译安装Lua-JIT环境

make PREFIX=/usr/local/luajit

make install PREFIX=/usr/local/luajit

设置环境变量:

export LUAJIT_LIB=/usr/local/luajit/lib

export LUAJIT_INC=/usr/local/luajit/include/luajit-2.1

2. 下载lua-nginx-module

3. 编译Nginx

./configure --prefix=/usr/local/nginx (这里填写你需要安装的模块) --add-module=/path/to/lua-nginx-module

make

make install

4.验证lua-nginx-module是否安装成功

修改Nginx配置:

location /hello_lua { 
  default_type 'text/plain'; 
  content_by_lua 'ngx.say("hello, lua")'; 
}

启动Nginx服务:

/usr/local/nginx/sbin/nginx

访问localhost/hello_lua查看浏览器能否显示数据

参见错误: error while loading shared libraries: libluajit-5.1.so.2: cannot open shared

解决方法: 重新安装libluajit-5.1这个库,ubuntu下使用apt即可安装,centos需要下载独立的rpm包

5.配置nginx-lua-prometheus模块

将以下代码放进Nginx配置文件的Http配置块里:

lua_shared_dict prometheus_metrics 10M;
lua_package_path "/path/to/nginx-lua-prometheus/?.lua";
init_by_lua '
prometheus = require("prometheus").init("prometheus_metrics")
metric_requests = prometheus:counter(
    "nginx_http_requests_total", "Number of HTTP requests", {"host", "status"})
metric_latency = prometheus:histogram(
    "nginx_http_request_duration_seconds", "HTTP request latency", {"host"})
metric_connections = prometheus:gauge(
    "nginx_http_connections", "Number of HTTP connections", {"state"})
';
log_by_lua '
local host = ngx.var.host:gsub("^www.", "")
metric_requests:inc(1, {host, ngx.var.status})
metric_latency:observe(ngx.now() - ngx.req.start_time(), {host})
';

注意第二行修改你本机的nginx-lua-prometheus模块位置

使用命令检查配置是否正确:

/usr/local/nginx/sbin/nginx -t

配置Nginx的监听端口:

server {
    listen 9145;
    location /metrics {
        content_by_lua '
        metric_connections:set(ngx.var.connections_reading, {"reading"})
        metric_connections:set(ngx.var.connections_waiting, {"waiting"})
        metric_connections:set(ngx.var.connections_writing, {"writing"})
        prometheus:collect()
        ';
    }
}

注意在生产环境中要设置只允许prometheus server能够访问这个端口

使用命令检查配置是否正确:

/usr/local/nginx/sbin/nginx -t

若准确无误,更新Nginx服务

/usr/local/nginx -s reload

至此Nginx配置完成